纵轴式掘进机垂直振动模型及座椅舒适性分析

Vertical vibration model and seat comfort analysis for longitudinal axis roadheader

为了研究纵轴式掘进机截割时的垂直振动情况和司机的舒适性,建立了掘进机整机-座椅的阻尼减振模型,以国际标准ISO 2631作为舒适性评价指标,在掘进机横扫和钻进2种典型工况下,分析了座椅系统的刚度-阻尼参数特性,确定其最优匹配关系;对比研究了3组刚度-阻尼参数配置座椅(Ⅰ组-原刚性座椅参数配置、Ⅱ组-"稍有不适"参数配置和Ⅲ组-"无不适感觉"参数配置)的振动耗散能力。结果表明:刚性座椅Ⅰ的垂直加权加速度均方根大于0.8,司机主观感觉为不舒适,与试验结果吻合;在限定座椅共振频率条件下,当座椅刚度系数大于7×10^5N/m,座椅阻尼系数大于3.4×10^4N·s/m时,2种工况下座椅垂直加权加速度均方根小于0.315,司机主观感觉为无不适感觉。相比刚性座椅Ⅰ组,阻尼座椅Ⅱ组和Ⅲ组的垂直加速度均方根分别降低了35.7%、50.9%(横扫工况)和38.7%、54.9%(钻进工况),频响峰值分别降低了73.8%、92.4%(横扫工况)和74.9%、92.8%(钻进工况),说明司机阻尼座椅的舒适性得到了很大改善,2种工况下的振动耗散能力接近,且与参数匹配结果一致。对截割力和座椅响应的频域特性分析发现,截割力一阶频率为1.66 Hz,与座椅响应的峰值频率1.65 Hz接近,是影响司机座椅舒适性的主要载荷成分,这些分析结果可为掘进机高性能阻尼座椅的动态设计和优化提供参考。

In order to understand the vertical vibration feature of the longitudinal axis roadheader and the comfort of the driver in cutting conditions,a damping vibration reduction model of the roadheader was established,and the international standard ISO 2631 was taken as the comfort evaluation index. Under two typical working conditions of the roadheader,i.e. sweeping and drilling,the stiffness-damping parameter characteristics of the seat system were analyzed to determine the optimal matching relationship. The vibration dissipation capabilities of various parameter configurations( I-original rigid seat parameter configuration,Ⅱ-"slightly discomfort"parameter configuration and Ⅲ-" comfort" parameter configuration) were compared and studied. The results show that the Root Mean Square( RMS) of the vertical weighted acceleration of the rigid seat I is greater than 0.8,and the driver’s subjective feeling is " uncomfortable",which is consistent with the experimental result;when the seat stiffness coefficient is greater than 700 000 N/m and the damping coefficient is greater than34 000 N·s/m,the RMS of the vertical weighted acceleration of the seat under the two working conditions is less than 0.315 and the driver’s subjective feeling is " comfort". Compared with the rigid seat I,the RMS of vertical acceleration of damping seats ⅡI and Ⅲ decreased by 35.7%,50.9%( sweeping condition) and 38.7%,54.9%( drilling condition) respectively,and the peak frequency response decreased by 73.8%,92.4%( sweeping condition) and 74.9%,92.8%( drilling condition) respectively,indicating that the comfort of the driver of damping seats Ⅱ and Ⅲ has been greatly improved and the vibration dissipation capability is close to each other,which is consistent with the parameter matching results. By analyzing the frequency characteristics of cutting force and seat response,it is found that the first-order frequency of the cutting force is 1.66 Hz,which is close to the peak frequency of seat response of 1.65 Hz,implying that the cutting effect is the main component affecting the driver’s comfort. This study could provide reference for dynamic design and optimization of high performance damping seat of roadheader.